1. Field of the Invention
The present invention relates to an endoscope to be inserted in a body cavity appropriate for observing vessels, an endoscopic apparatus, and an examination method of using the endoscope.
2. Description of the Related Art
Recently, endoscopes have been widely used in the medical field. Surgeons use the endoscopes to find and examine a lesion.
For example, cancers, as an example of lesion, tend to develop and cluster in vessels including a capillary vessel in a near-surface region of a living organ. Using an endoscope, a surgeon determines the presence or absence of a capillary vessel in the near-surface layer of the living organ and observes a network of the capillary vessel using the endoscope. The use of the endoscope in this way is becoming an effective method to determine whether a lesion is a cancer.
Thus, observing vessels containing capillary vessels in the near-surface layer of the living organ should be easy. However, the capillary vessel is too tiny to observe. More specifically, since the capillary vessel appears and disappears in synchronization with heart beat, it is difficult to observe it.
United States Patent Application Publication No. 2004/0266713 discloses means for promoting the supply of blood flow by using hypodermic injection.
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